A Novel Soft-Switched Three-Phase Single-Switch Rectifier

A new, soft-switched, three-phase, single-switch buck converter is proposed in this paper. The converter is a zero-current-switching (ZCS) quasi-resonant type converter that can operate with significantly less switching frequency variation than previously proposed converters of the same type. In the paper, the operation of conventional three-phase single-switch boost and buck converters are first reviewed, the mechanism by which the variation in switching frequency can be reduced is discussed, and the operation of the proposed converter is explained. The feasibility of the new converter is confirmed with results obtained from an experimental prototype.